SAN JOSE, Calif. (AP) — The resignation of Mozilla's CEO amid outrage that he supported an anti-gay marriage campaign is prompting concerns about how Silicon Valley's strongly liberal culture might quash the very openness that is at the region's foundation.Mozilla co-founder Brendan Eich stepped down Thursday as CEO, just days after his appointment. He left the nonprofit maker of the Firefox browser after furious attacks, largely on Twitter, over his $1,000 contribution to support of a now-overturned 2008 gay-marriage ban in California."There was no interest in creating an Internet lynch mob," OkCupid co-founder Sam Yagun, whose dating service site was among those engaged in online protest, said Friday. "I am opposed to that with every bone in my body."But Eich’s abrupt departure has stirred the debate over the fairness of forcing out a highly qualified technology executive over his personal views and a single campaign contribution six years ago.